[Rescue balloon pulmonary angioplasty for a patient with acute exacerbation of chronic thromboembolic pulmonary hypertension supported by extracorporeal membrane oxygenation: a case report]

A 33-year-old male patient was admitted to hospital because of "dyspnea after activity for 3 years and aggravation for 15 days". With a history of membranous nephropathy, irregular anticoagulation led to acute exacerbation of Chronic thromboembolic pulmonary hypertension(CTEPH) and acute respiratory failure, and endotracheal intubation and mechanical ventilation was given. Although treated with thrombolysis and adequate anticoagulation, the condition worsened and hemodynamics deteriorated, and then VA-ECMO was performed. Due to severe pulmonary hypertension and right heart failure,ECMO could not be weaned off, and the patient subsequently developed pulmonary infection, right lung hemorrhage, hyperbilirubinemia, coagulation dysfunction and other complications. Then the patient was transferred to our hospital by airplane, and multidisciplinary discussions were quickly arranged after admission. Considering that the patient was critically ill and complicated with multiple organ failure, pulmonary endarterectomy (PEA) could not be tolerated, rescue balloon pulmonary angioplasty (BPA) was recommended and performed on the second day after admission. The mean pulmonary artery pressure was 59 mmHg(1 mmHg=0.133 kPa) measured by right heart catheterization, and pulmonary angiography showed that the main pulmonary artery was dilated, while the right lower pulmonary artery was completely occluded, and there were multiple stenoses in the branches of the right upper lobe, middle lobe pulmonary artery and the left pulmonary artery. BPA was performed on a total of 9 pulmonary arteries. VA-ECMO was weaned off on day 6 after admission, and the mechanical ventilation was weaned off on day 41 after admission. The patient was successfully discharged on day 72 after admission. Rescue BPA was an effective treatment for severe CTEPH patients who could not be treated with PEA.

[Effects of transient receptor potential vanilloid type 4-specific activator on human vascular endothelial cell functions and blood supply of rat perforator flap and its mechanism]

Objective: To analyze the effects of transient receptor potential vanilloid type 4 (TRPV4) activation on the function and endothelial-to-mesenchymal transition (EndMT) of human umbilical vein endothelial cells (HUVECs), as well as to explore the effects of TRPV4 activation on blood perfusion and survival of rat perforator flap and the mechanism. Methods: The experimental research methods were used. The 3rd to 6th passages of HUVECs were used for experiments and divided into 0.5 μmol/L 4α-phorbol 12, 13-didecanoate (4αPDD) group, 1.0 μmol/L 4αPDD group, 3.0 μmol/L 4αPDD group, 10.0 μmol/L 4αPDD group, and phosphate buffer solution (PBS) group, which were cultivated in corresponding final molarity of 4αPDD and PBS, respectively. The cell proliferation activity at 6 and 12 h of culture was detected using cell counting kit-8 (CCK-8). Another batch of cells was acquired and divided into PBS group, 1 μmol/L 4αPDD group, and 3 μmol/L 4αPDD group, which were treated similarly as described before and then detected for cell proliferation activity at 6, 12, 24, and 48 h of culture. The residual scratch area of cells at post scratch hour (PSH) 12, 24, and 48 was detected by scratch test, and the percentage of the residual scratch area was calculated. The number of migrated cells at 24 and 48 h of culture was detected by Transwell experiment. The tube-formation assay was used to measure the number of tubular structures at 4 and 8 h of culture. The protein expressions of E-cadherin, N-cadherin, Slug, and Snail at 24 h of culture were detected by Western blotting. All the sample numbers in each group at each time point in vitro experiments were 3. A total of 36 male Sprague-Dawley rats aged 8 to 10 weeks were divided into delayed flap group, 4αPDD group, and normal saline group according to the random number table, with 12 rats in each group, and iliolumbar artery perforator flap models on the back were constructed. The flap surgical delay procedure was only performed in the rats in delayed flap group one week before the flap transfer surgery. Neither rats in 4αPDD group nor normal saline group had flap surgical delay; instead, they were intraperitoneally injected with 4αPDD and an equivalent mass of normal saline, respectively, at 10 min before, 24 h after, and 48 h after the surgery. The general state of flap was observed on post surgery day (PSD) 0 (immediately), 1, 4, and 7. The flap survival rates were assessed on PSD 7. The flap blood perfusion was detected by laser speckle contrast imaging technique on PSD 1, 4, and 7. The microvascular density in the flap's choke vessel zone was detected by immunohistochemical staining. All the sample numbers in each group at each time point in vivo experiments were 12. Data were statistically analyzed with analysis of variance for factorial design, analysis of variance for repeated measurement, one-way analysis of variance, least significant difference t test, and Bonferroni correction. Results: At 6 and 12 h of culture, there were no statistically significant differences in cell proliferation activity in the overall comparison among PBS group, 0.5 μmol/L 4αPDD group, 1.0 μmol/L 4αPDD group, 3.0 μmol/L 4αPDD group, and 10.0 μmol/L 4αPDD group (P>0.05). At 6, 12, 24, and 48 h of culture, there were no statistically significant differences in cell proliferation activity in the overall comparison among PBS group, 1 μmol/L 4αPDD group, and 3 μmol/L 4αPDD group (P>0.05). At PSH 12, the percentages of the residual scratch area of cells in 1 μmol/L 4αPDD group and 3 μmol/L 4αPDD group were close to that in PBS group (P>0.05). At PSH 24 and 48, compared with those in PBS group, the percentages of the residual scratch area of cells in 3 μmol/L 4αPDD group were significantly decreased (with t values of 2.83 and 2.79, respectively, P<0.05), while the percentages of the residual scratch area of cells in 1 μmol/L 4αPDD group showed no significant differences (P>0.05). At 24 h of culture, the number of migrated cells in 1 μmol/L 4αPDD group and 3 μmol/L 4αPDD group were close to that in PBS group (P>0.05). At 48 h of culture, the number of migrated cells in 1 μmol/L 4αPDD group and 3 μmol/L 4αPDD groups were significantly greater than that in PBS group (with t values of 6.20 and 9.59, respectively, P<0.01). At 4 h of culture, the numbers of tubular structures of cells in 1 μmol/L 4αPDD group and 3 μmol/L 4αPDD group were significantly greater than that in PBS group (with t values of 4.68 and 4.95, respectively, P<0.05 or <0.01). At 8 h of culture, the numbers of tubular structures of cells in 1 μmol/L 4αPDD and 3 μmol/L 4αPDD groups were similar to that in PBS group (P>0.05). At 24 h of culture, compared with those in PBS group, the protein expression level of E-cadherin of cells in 3 μmol/L 4αPDD group was significantly decreased (t=5.13, P<0.01), whereas there was no statistically significant difference in the protein expression level of E-cadherin of cells in 1 μmol/L 4αPDD group (P>0.05); the protein expression level of N-cadherin of cells in 3 μmol/L 4αPDD group was significantly increased (t=4.93, P<0.01), whereas there was no statistically significant difference in the protein expression level of N-cadherin of cells in 1 μmol/L 4αPDD group (P>0.05); the protein expression levels of Slug of cells in 1 μmol/L 4αPDD group and 3 μmol/L 4αPDD group were significantly increased (with t values of 3.85 and 6.52, respectively, P<0.05 or P<0.01); and the protein expression level of Snail of cells in 3 μmol/L 4αPDD group was significantly increased (t=4.08, P<0.05), whereas there was no statistically significant difference in the protein expression level of Snail of cells in 1 μmol/L 4αPDD group (P>0.05). There were no statistically significant differences in the protein expression levels of E-cadherin, N-cadherin, Slug, or Snail of cells between 1 μmol/L 4αPDD group and 3 μmol/L 4αPDD group (P>0.05). The general condition of flaps of rats in the three groups was good on PSD 0. On PSD 1, the flaps of rats in the three groups were basically similar, with bruising and swelling at the distal end. On PSD 4, the swelling of flaps of rats in the three groups subsided, and the distal end turned dark brown and necrosis occurred, with the area of necrosis in flaps of rats in normal saline group being larger than the areas in 4αPDD group and delayed flap group. On PSD 7, the necrotic areas of flaps of rats in the 3 groups were fairly stable, with the area of necrosis at the distal end of flap of rats in delayed flap group being the smallest. On PSD 7, the flap survival rates of rats in 4αPDD group ((80±13)%) and delayed flap group ((87±9)%) were similar (P>0.05), and both were significantly higher than (70±11)% in normal saline group (with t values of 2.24 and 3.65, respectively, P<0.05 or P<0.01). On PSD 1, the overall blood perfusion signals of rats in the 3 groups were basically the same, and the blood perfusion signals in the choke vessel zone were relatively strong, with a certain degree of underperfusion at the distal end. On PSD 4, the boundary between the surviving and necrotic areas of flaps of rats in the 3 groups became evident, and the blood perfusion signals in the choke vessel zone were improved, with the normal saline group's distal hypoperfused area of flap being larger than the areas in delayed flap group and 4αPDD group. On PSD 7, the blood perfusion signals of overall flap of rats had generally stabilized in the 3 groups, with the intensity of blood perfusion signal in the choke vessel zone and overall flap of rats in delayed flap group and 4αPDD group being significantly greater than that in normal saline group. On PSD 7, the microvascular density in the choke vessel zone of flap of rats in 4αPDD group and delayed flap group were similar (P>0.05), and both were significantly higher than that in normal saline group (with t values of 4.11 and 5.38, respectively, P<0.01). Conclusions: After activation, TRPV4 may promote the migration and tubular formation of human vascular endothelial cells via the EndMT pathway, leading to the enhanced blood perfusion of perforator flap and microvascular density in the choke vessel zone, and therefore increase the flap survival rate.

[Clinical application of expanded internal mammary artery perforator flap combined with vascular supercharge in reconstruction of faciocervical scar]

Objective: To summarize the clinical experience of expanded internal mammary artery perforator (IMAP) flap combined with vascular supercharge in reconstruction of faciocervical scar. Methods: The retrospective observational study was conducted. From September 2012 to May 2021, 23 patients with postburn or posttraumatic faciocervical scars who met the inclusion criteria were admitted to Shanghai Ninth People's Hospital of Shanghai Jiao Tong University School of Medicine, including 18 males and 5 females, aged from 11 to 58 years, all of whom were reconstructed with expanded IMAP flaps. At the first stage, one or two skin and soft tissue expander (s) with appropriate rated capacity were implanted in the anterior chest area according to the location and size of the scars. The IMAP, thoracic branch of supraclavicular artery, and lateral thoracic artery were preserved during the operation. The skin and soft tissue expanders were inflated with normal saline after the operation. The flaps were transferred during the second stage. The dominant IMAP was determined preoperatively using color Doppler ultrasound (CDU) blood flow detector. The faciocervical scars were removed, forming wounds with areas of 9 cm×7 cm-28 cm×12 cm, and the perforators of superficial temporal artery and vein or facial artery and vein were preserved during the operation. The flaps were designed according to the area and size of the wounds after scar resection with the dominant IMAP as the pedicle. Single-pedicle IMAP flaps were used to repair small and medium-sized wounds. For larger defects, the blood perfusion areas of vessels in the anterior chest were evaluated by indocyanine green angiography (ICGA). In situations where the IMAP was insufficient to nourish the entire flap, double-pedicle flaps were designed by using the thoracic branch of supraclavicular artery or lateral thoracic artery for supercharging. Pedicled or free flap transfer was selected according to the distance between the donor areas and recipient areas. After transplantation of flaps, ICGA was conducted again to evaluate blood perfusion of the flaps. The donor sites of flaps were all closed by suturing directly. Statistics were recorded, including the number, rated capacity, normal saline injection volume, and expansion period of skin and soft tissue expanders, the location of the dominant IMAP, the total number of the flaps used, the number of flaps with different types of vascular pedicles, the flap area, the flap survival after the second stage surgery, the occurrence of common complications in the donor and recipient areas, and the condition of follow-up. Results: Totally 25 skin and soft tissue expanders were used in this group of patients, with rated capacity of 200-500 mL, normal saline injection volume of 855-2 055 mL, and expansion period of 4-16 months. The dominant IMAP was detected in the second intercostal space (20 sides) or the third intercostal space (5 sides) before surgery. A total of 25 expanded flaps were excised, including 2 pedicled IMAP flaps, 11 free IMAP flaps, 4 pedicled thoracic branch of supraclavicular artery+free IMAP flaps, and 8 free IMAP+lateral thoracic artery flaps, with flap areas of 10 cm×8 cm-30 cm×14 cm. After the second stage surgery, tip necrosis of flaps in three patients occurred, which healed after routine dressing changes; one patient developed arterial embolism and local torsion on the vascular pedicle at the anastomosis of IMAP and facial artery, and the blood supply recovered after thrombectomy and vascular re-anastomosis. Fourteen patients underwent flap thinning surgery in 1 month to 6 months after the second stage surgery. The follow-up for 4 months to 9 years showed that all patients had improved appearances of flaps and functions of face and neck and linear scar in the donor sites of flaps, and one female patient had obvious nipple displacement and bilateral breast asymmetry. Conclusions: The expanded IMAP flap is matched in color and texture with that of the face and neck, and its incision causes little damage to the chest donor sites. When combined with vascular supercharge, a double-pedicle flap can be designed flexibly to further enhance the blood supply and expand the flap incision area, which is a good choice for reconstruction of large faciocervical scar.

[Etiology of severe community-acquired pneumonia in immunocompromised patients]

Objective: To analyze the etiology of severe community-acquired pneumonia (SCAP) in immunocompromised patients, and to investigate the relationship between underlying diseases and infectious microorganisms. Methods: A retrospective analysis was performed on SCAP in immunocompromised patients admitted to the Fourth Department of Respiratory and Critical Medicine (MICU) of China-Japan Friendship Hospital from January 1, 2017 to December 31, 2019. A total of 119 SCAP patients were finally enrolled, including 65 males (54.6%), with an average age of (59.3±14.5) years. The average of Sequential Organ Failure Assessment (SOFA) score was 6.7±3.6 and the acute physiology and chronic health evaluation (APACHE) Ⅱ score was 19.4±6.8. Sixty (50%) of these patients were finally improved and discharged. Long-term glucocorticoid treatment was the main risk factor for immunocompromise. The difference of pathogenic microorganisms between patients with and without structural lung diseases, and the influence of different pathogenic microorganisms on hospital mortality were calculated, respectively. P<0.05 was considered to be statistically significant. Results: In this study, 99 (83.2%) patients were identified to have positive etiological results, and the incidence of concurrent infection was 54.5%. The top three pathogens were Pneumocystis Jiroveci (55.6%), Cytomegalovirus (47.5%) and Aspergillus (23.2%). Staphylococcus aureus was the most common bacterium, followed by Pseudomonas aeruginosa and Klebsiella pneumoniae. The risk of Pneumocystis Jiroveci infection was significantly higher in patients without underlying lung diseases as compared to those with underlying lung diseases (64.3% vs. 44.2%, P = 0.046). The in-hospital mortality was not different among patients infected with different pathogens(all P>0.05), but was higher in those with mixed infections(56.7% vs. 33.9%, P=0.013). Conclusions: Pneumocystis Jiroveci and Cytomegalovirus were the most common pathogens in immunocompromised patients with severe community-acquired pneumonia, and the incidence of Pneumocystis Jiroveci was significantly higher in patients without underlying lung diseases.